diff mbox series

[netnext,8/8] net: dsa: mt7530: simplify link operations and force link down on all ports

Message ID 20240208-for-netnext-mt7530-improvements-3-v1-8-d7c1cfd502ca@arinc9.com
State New
Headers
Series MT7530 DSA Subdriver Improvements Act III |

Commit Message

Arınç ÜNAL via B4 Relay Feb. 8, 2024, 5:51 a.m. UTC 
  From: Arınç ÜNAL <arinc.unal@arinc9.com>

Currently, the link operations for switch MACs are scattered across
port_enable, port_disable, phylink_mac_config, phylink_mac_link_up, and
phylink_mac_link_down.

port_enable and port_disable clears the link settings. Move that to
mt7530_setup() and mt7531_setup_common() which set up the switches. This
way, the link settings are cleared on all ports at setup, and then only
once with phylink_mac_link_down() when a link goes down.

Enable force mode at setup to apply the force part of the link settings.
This ensures that only active ports will have their link up.

Now that the bit for setting the port on force mode is done on
mt7530_setup() and mt7531_setup_common(), get rid of PMCR_FORCE_MODE_ID()
which helped determine which bit to use for the switch model.

The "MT7621 Giga Switch Programming Guide v0.3", "MT7531 Reference Manual
for Development Board v1.0", and "MT7988A Wi-Fi 7 Generation Router
Platform: Datasheet (Open Version) v0.1" documents show that these bits are
enabled at reset:

PMCR_IFG_XMIT(1) (not part of PMCR_LINK_SETTINGS_MASK)
PMCR_MAC_MODE (not part of PMCR_LINK_SETTINGS_MASK)
PMCR_TX_EN
PMCR_RX_EN
PMCR_BACKOFF_EN (not part of PMCR_LINK_SETTINGS_MASK)
PMCR_BACKPR_EN (not part of PMCR_LINK_SETTINGS_MASK)
PMCR_TX_FC_EN
PMCR_RX_FC_EN

These bits also don't exist on the MT7530_PMCR_P(6) register of the switch
on the MT7988 SoC:

PMCR_IFG_XMIT()
PMCR_MAC_MODE
PMCR_BACKOFF_EN
PMCR_BACKPR_EN

Remove the setting of the bits not part of PMCR_LINK_SETTINGS_MASK on
phylink_mac_config as they're already set.

Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
---
 drivers/net/dsa/mt7530.c | 26 +++++++++++++-------------
 drivers/net/dsa/mt7530.h |  2 --
 2 files changed, 13 insertions(+), 15 deletions(-)

Comments

Daniel Golle Feb. 8, 2024, 4:22 p.m. UTC | #1 
On Thu, Feb 08, 2024 at 08:51:36AM +0300, Arınç ÜNAL via B4 Relay wrote:
> From: Arınç ÜNAL <arinc.unal@arinc9.com>
> 
> Currently, the link operations for switch MACs are scattered across
> port_enable, port_disable, phylink_mac_config, phylink_mac_link_up, and
> phylink_mac_link_down.
> 
> port_enable and port_disable clears the link settings. Move that to
> mt7530_setup() and mt7531_setup_common() which set up the switches. This
> way, the link settings are cleared on all ports at setup, and then only
> once with phylink_mac_link_down() when a link goes down.
> 
> Enable force mode at setup to apply the force part of the link settings.
> This ensures that only active ports will have their link up.
> 
> Now that the bit for setting the port on force mode is done on
> mt7530_setup() and mt7531_setup_common(), get rid of PMCR_FORCE_MODE_ID()
> which helped determine which bit to use for the switch model.
> 
> The "MT7621 Giga Switch Programming Guide v0.3", "MT7531 Reference Manual
> for Development Board v1.0", and "MT7988A Wi-Fi 7 Generation Router
> Platform: Datasheet (Open Version) v0.1" documents show that these bits are
> enabled at reset:
> 
> PMCR_IFG_XMIT(1) (not part of PMCR_LINK_SETTINGS_MASK)
> PMCR_MAC_MODE (not part of PMCR_LINK_SETTINGS_MASK)
> PMCR_TX_EN
> PMCR_RX_EN
> PMCR_BACKOFF_EN (not part of PMCR_LINK_SETTINGS_MASK)
> PMCR_BACKPR_EN (not part of PMCR_LINK_SETTINGS_MASK)
> PMCR_TX_FC_EN
> PMCR_RX_FC_EN
> 
> These bits also don't exist on the MT7530_PMCR_P(6) register of the switch
> on the MT7988 SoC:
> 
> PMCR_IFG_XMIT()
> PMCR_MAC_MODE
> PMCR_BACKOFF_EN
> PMCR_BACKPR_EN
> 
> Remove the setting of the bits not part of PMCR_LINK_SETTINGS_MASK on
> phylink_mac_config as they're already set.
> 
> Suggested-by: Vladimir Oltean <olteanv@gmail.com>
> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
> ---
>  drivers/net/dsa/mt7530.c | 26 +++++++++++++-------------
>  drivers/net/dsa/mt7530.h |  2 --
>  2 files changed, 13 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> index 5c8ad41ce8cd..f67db577d1c0 100644
> --- a/drivers/net/dsa/mt7530.c
> +++ b/drivers/net/dsa/mt7530.c
> @@ -1018,7 +1018,6 @@ mt7530_port_enable(struct dsa_switch *ds, int port,
>  	priv->ports[port].enable = true;
>  	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
>  		   priv->ports[port].pm);
> -	mt7530_clear(priv, MT7530_PMCR_P(port), PMCR_LINK_SETTINGS_MASK);
>  
>  	mutex_unlock(&priv->reg_mutex);
>  
> @@ -1038,7 +1037,6 @@ mt7530_port_disable(struct dsa_switch *ds, int port)
>  	priv->ports[port].enable = false;
>  	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
>  		   PCR_MATRIX_CLR);
> -	mt7530_clear(priv, MT7530_PMCR_P(port), PMCR_LINK_SETTINGS_MASK);
>  
>  	mutex_unlock(&priv->reg_mutex);
>  }
> @@ -2257,6 +2255,12 @@ mt7530_setup(struct dsa_switch *ds)
>  	mt7530_mib_reset(ds);
>  
>  	for (i = 0; i < MT7530_NUM_PORTS; i++) {
> +		/* Clear link settings and enable force mode to force link down
> +		 * on all ports until they're enabled later.
> +		 */
> +		mt7530_clear(priv, MT7530_PMCR_P(i), PMCR_LINK_SETTINGS_MASK);
> +		mt7530_set(priv, MT7530_PMCR_P(i), PMCR_FORCE_MODE);

Any reason to not combine the two lines above into a single call:

mt7530_rmw(priv, MT7530_PMCR_P(i),
	   PMCR_LINK_SETTINGS_MASK | PMCR_FORCE_MODE,
	   PMCR_FORCE_MODE);

> +
>  		/* Disable forwarding by default on all ports */
>  		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
>  			   PCR_MATRIX_CLR);
> @@ -2359,6 +2363,12 @@ mt7531_setup_common(struct dsa_switch *ds)
>  		     UNU_FFP_MASK);
>  
>  	for (i = 0; i < MT7530_NUM_PORTS; i++) {
> +		/* Clear link settings and enable force mode to force link down
> +		 * on all ports until they're enabled later.
> +		 */
> +		mt7530_clear(priv, MT7530_PMCR_P(i), PMCR_LINK_SETTINGS_MASK);
> +		mt7530_set(priv, MT7530_PMCR_P(i), MT7531_FORCE_MODE);
> +

Same here obviously.

>  		/* Disable forwarding by default on all ports */
>  		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
>  			   PCR_MATRIX_CLR);
> @@ -2657,23 +2667,13 @@ mt753x_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
>  			  const struct phylink_link_state *state)
>  {
>  	struct mt7530_priv *priv = ds->priv;
> -	u32 mcr_cur, mcr_new;
>  
>  	if ((port == 5 || port == 6) && priv->info->mac_port_config)
>  		priv->info->mac_port_config(ds, port, mode, state->interface);
>  
> -	mcr_cur = mt7530_read(priv, MT7530_PMCR_P(port));
> -	mcr_new = mcr_cur;
> -	mcr_new &= ~PMCR_LINK_SETTINGS_MASK;
> -	mcr_new |= PMCR_IFG_XMIT(1) | PMCR_MAC_MODE | PMCR_BACKOFF_EN |
> -		   PMCR_BACKPR_EN | PMCR_FORCE_MODE_ID(priv->id);
> -
>  	/* Are we connected to external phy */
>  	if (port == 5 && dsa_is_user_port(ds, 5))
> -		mcr_new |= PMCR_EXT_PHY;
> -
> -	if (mcr_new != mcr_cur)
> -		mt7530_write(priv, MT7530_PMCR_P(port), mcr_new);
> +		mt7530_set(priv, MT7530_PMCR_P(port), PMCR_EXT_PHY);
>  }
>  
>  static void mt753x_phylink_mac_link_down(struct dsa_switch *ds, int port,
> diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
> index 8a8144868eaa..a71166e0a7fc 100644
> --- a/drivers/net/dsa/mt7530.h
> +++ b/drivers/net/dsa/mt7530.h
> @@ -304,8 +304,6 @@ enum mt7530_vlan_port_acc_frm {
>  					 MT7531_FORCE_DPX | \
>  					 MT7531_FORCE_RX_FC | \
>  					 MT7531_FORCE_TX_FC)
> -#define  PMCR_FORCE_MODE_ID(id)		((((id) == ID_MT7531) || ((id) == ID_MT7988)) ?	\
> -					 MT7531_FORCE_MODE : PMCR_FORCE_MODE)
>  #define  PMCR_LINK_SETTINGS_MASK	(PMCR_TX_EN | PMCR_FORCE_SPEED_1000 | \
>  					 PMCR_RX_EN | PMCR_FORCE_SPEED_100 | \
>  					 PMCR_TX_FC_EN | PMCR_RX_FC_EN | \
> 
> -- 
> 2.40.1
>
Arınç ÜNAL Feb. 8, 2024, 7:35 p.m. UTC | #2 
On 8.02.2024 19:22, Daniel Golle wrote:
> On Thu, Feb 08, 2024 at 08:51:36AM +0300, Arınç ÜNAL via B4 Relay wrote:
>> From: Arınç ÜNAL <arinc.unal@arinc9.com>
>>
>> Currently, the link operations for switch MACs are scattered across
>> port_enable, port_disable, phylink_mac_config, phylink_mac_link_up, and
>> phylink_mac_link_down.
>>
>> port_enable and port_disable clears the link settings. Move that to
>> mt7530_setup() and mt7531_setup_common() which set up the switches. This
>> way, the link settings are cleared on all ports at setup, and then only
>> once with phylink_mac_link_down() when a link goes down.
>>
>> Enable force mode at setup to apply the force part of the link settings.
>> This ensures that only active ports will have their link up.
>>
>> Now that the bit for setting the port on force mode is done on
>> mt7530_setup() and mt7531_setup_common(), get rid of PMCR_FORCE_MODE_ID()
>> which helped determine which bit to use for the switch model.
>>
>> The "MT7621 Giga Switch Programming Guide v0.3", "MT7531 Reference Manual
>> for Development Board v1.0", and "MT7988A Wi-Fi 7 Generation Router
>> Platform: Datasheet (Open Version) v0.1" documents show that these bits are
>> enabled at reset:
>>
>> PMCR_IFG_XMIT(1) (not part of PMCR_LINK_SETTINGS_MASK)
>> PMCR_MAC_MODE (not part of PMCR_LINK_SETTINGS_MASK)
>> PMCR_TX_EN
>> PMCR_RX_EN
>> PMCR_BACKOFF_EN (not part of PMCR_LINK_SETTINGS_MASK)
>> PMCR_BACKPR_EN (not part of PMCR_LINK_SETTINGS_MASK)
>> PMCR_TX_FC_EN
>> PMCR_RX_FC_EN
>>
>> These bits also don't exist on the MT7530_PMCR_P(6) register of the switch
>> on the MT7988 SoC:
>>
>> PMCR_IFG_XMIT()
>> PMCR_MAC_MODE
>> PMCR_BACKOFF_EN
>> PMCR_BACKPR_EN
>>
>> Remove the setting of the bits not part of PMCR_LINK_SETTINGS_MASK on
>> phylink_mac_config as they're already set.
>>
>> Suggested-by: Vladimir Oltean <olteanv@gmail.com>
>> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
>> ---
>>   drivers/net/dsa/mt7530.c | 26 +++++++++++++-------------
>>   drivers/net/dsa/mt7530.h |  2 --
>>   2 files changed, 13 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
>> index 5c8ad41ce8cd..f67db577d1c0 100644
>> --- a/drivers/net/dsa/mt7530.c
>> +++ b/drivers/net/dsa/mt7530.c
>> @@ -1018,7 +1018,6 @@ mt7530_port_enable(struct dsa_switch *ds, int port,
>>   	priv->ports[port].enable = true;
>>   	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
>>   		   priv->ports[port].pm);
>> -	mt7530_clear(priv, MT7530_PMCR_P(port), PMCR_LINK_SETTINGS_MASK);
>>   
>>   	mutex_unlock(&priv->reg_mutex);
>>   
>> @@ -1038,7 +1037,6 @@ mt7530_port_disable(struct dsa_switch *ds, int port)
>>   	priv->ports[port].enable = false;
>>   	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
>>   		   PCR_MATRIX_CLR);
>> -	mt7530_clear(priv, MT7530_PMCR_P(port), PMCR_LINK_SETTINGS_MASK);
>>   
>>   	mutex_unlock(&priv->reg_mutex);
>>   }
>> @@ -2257,6 +2255,12 @@ mt7530_setup(struct dsa_switch *ds)
>>   	mt7530_mib_reset(ds);
>>   
>>   	for (i = 0; i < MT7530_NUM_PORTS; i++) {
>> +		/* Clear link settings and enable force mode to force link down
>> +		 * on all ports until they're enabled later.
>> +		 */
>> +		mt7530_clear(priv, MT7530_PMCR_P(i), PMCR_LINK_SETTINGS_MASK);
>> +		mt7530_set(priv, MT7530_PMCR_P(i), PMCR_FORCE_MODE);
> 
> Any reason to not combine the two lines above into a single call:
> 
> mt7530_rmw(priv, MT7530_PMCR_P(i),
> 	   PMCR_LINK_SETTINGS_MASK | PMCR_FORCE_MODE,
> 	   PMCR_FORCE_MODE);

No reason whatsoever, I'll do this. Thanks!

Arınç
Russell King (Oracle) Feb. 16, 2024, 3:43 p.m. UTC | #3 
On Thu, Feb 08, 2024 at 08:51:36AM +0300, Arınç ÜNAL via B4 Relay wrote:
> From: Arınç ÜNAL <arinc.unal@arinc9.com>
> 
> Currently, the link operations for switch MACs are scattered across
> port_enable, port_disable, phylink_mac_config, phylink_mac_link_up, and
> phylink_mac_link_down.
> 
> port_enable and port_disable clears the link settings. Move that to
> mt7530_setup() and mt7531_setup_common() which set up the switches. This
> way, the link settings are cleared on all ports at setup, and then only
> once with phylink_mac_link_down() when a link goes down.
> 
> Enable force mode at setup to apply the force part of the link settings.
> This ensures that only active ports will have their link up.

I think we may have a different interpretation of what phylink's
mac_link_down() and mac_link_up() are supposed to be doing here.
Of course, you have read the documentation of these methods so are
fully aware of what they're supposed to do. So you are aware that
when inband mode is being used, forcing the link down may be
counter-productive depending on how the hardware works.
Arınç ÜNAL Feb. 16, 2024, 5:23 p.m. UTC | #4 
On 16.02.2024 18:43, Russell King (Oracle) wrote:
> On Thu, Feb 08, 2024 at 08:51:36AM +0300, Arınç ÜNAL via B4 Relay wrote:
>> From: Arınç ÜNAL <arinc.unal@arinc9.com>
>>
>> Currently, the link operations for switch MACs are scattered across
>> port_enable, port_disable, phylink_mac_config, phylink_mac_link_up, and
>> phylink_mac_link_down.
>>
>> port_enable and port_disable clears the link settings. Move that to
>> mt7530_setup() and mt7531_setup_common() which set up the switches. This
>> way, the link settings are cleared on all ports at setup, and then only
>> once with phylink_mac_link_down() when a link goes down.
>>
>> Enable force mode at setup to apply the force part of the link settings.
>> This ensures that only active ports will have their link up.
> 
> I think we may have a different interpretation of what phylink's
> mac_link_down() and mac_link_up() are supposed to be doing here.
> Of course, you have read the documentation of these methods so are
> fully aware of what they're supposed to do. So you are aware that
> when inband mode is being used, forcing the link down may be
> counter-productive depending on how the hardware works.

No, I haven't read the documentation [1] until your response here. My patch
here doesn't touch mt753x_phylink_mac_link_down(), it is already the case
with the driver that falls short of not forcing link down when inband mode
is being used.

That said, what I explain on the patch log does not properly describe the
driver behaviour. This should explain it correctly:

Enable force mode at setup to apply the force part of the link settings.
This ensures that the ports that were never active will have their link
down.

I could, in the future, study this thoroughly to make the driver fully
conform to the documentation.

[1] https://docs.kernel.org/networking/kapi.html#phylink

Arınç
diff mbox series

Patch

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 5c8ad41ce8cd..f67db577d1c0 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1018,7 +1018,6 @@  mt7530_port_enable(struct dsa_switch *ds, int port,
 	priv->ports[port].enable = true;
 	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
 		   priv->ports[port].pm);
-	mt7530_clear(priv, MT7530_PMCR_P(port), PMCR_LINK_SETTINGS_MASK);
 
 	mutex_unlock(&priv->reg_mutex);
 
@@ -1038,7 +1037,6 @@  mt7530_port_disable(struct dsa_switch *ds, int port)
 	priv->ports[port].enable = false;
 	mt7530_rmw(priv, MT7530_PCR_P(port), PCR_MATRIX_MASK,
 		   PCR_MATRIX_CLR);
-	mt7530_clear(priv, MT7530_PMCR_P(port), PMCR_LINK_SETTINGS_MASK);
 
 	mutex_unlock(&priv->reg_mutex);
 }
@@ -2257,6 +2255,12 @@  mt7530_setup(struct dsa_switch *ds)
 	mt7530_mib_reset(ds);
 
 	for (i = 0; i < MT7530_NUM_PORTS; i++) {
+		/* Clear link settings and enable force mode to force link down
+		 * on all ports until they're enabled later.
+		 */
+		mt7530_clear(priv, MT7530_PMCR_P(i), PMCR_LINK_SETTINGS_MASK);
+		mt7530_set(priv, MT7530_PMCR_P(i), PMCR_FORCE_MODE);
+
 		/* Disable forwarding by default on all ports */
 		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
 			   PCR_MATRIX_CLR);
@@ -2359,6 +2363,12 @@  mt7531_setup_common(struct dsa_switch *ds)
 		     UNU_FFP_MASK);
 
 	for (i = 0; i < MT7530_NUM_PORTS; i++) {
+		/* Clear link settings and enable force mode to force link down
+		 * on all ports until they're enabled later.
+		 */
+		mt7530_clear(priv, MT7530_PMCR_P(i), PMCR_LINK_SETTINGS_MASK);
+		mt7530_set(priv, MT7530_PMCR_P(i), MT7531_FORCE_MODE);
+
 		/* Disable forwarding by default on all ports */
 		mt7530_rmw(priv, MT7530_PCR_P(i), PCR_MATRIX_MASK,
 			   PCR_MATRIX_CLR);
@@ -2657,23 +2667,13 @@  mt753x_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
 			  const struct phylink_link_state *state)
 {
 	struct mt7530_priv *priv = ds->priv;
-	u32 mcr_cur, mcr_new;
 
 	if ((port == 5 || port == 6) && priv->info->mac_port_config)
 		priv->info->mac_port_config(ds, port, mode, state->interface);
 
-	mcr_cur = mt7530_read(priv, MT7530_PMCR_P(port));
-	mcr_new = mcr_cur;
-	mcr_new &= ~PMCR_LINK_SETTINGS_MASK;
-	mcr_new |= PMCR_IFG_XMIT(1) | PMCR_MAC_MODE | PMCR_BACKOFF_EN |
-		   PMCR_BACKPR_EN | PMCR_FORCE_MODE_ID(priv->id);
-
 	/* Are we connected to external phy */
 	if (port == 5 && dsa_is_user_port(ds, 5))
-		mcr_new |= PMCR_EXT_PHY;
-
-	if (mcr_new != mcr_cur)
-		mt7530_write(priv, MT7530_PMCR_P(port), mcr_new);
+		mt7530_set(priv, MT7530_PMCR_P(port), PMCR_EXT_PHY);
 }
 
 static void mt753x_phylink_mac_link_down(struct dsa_switch *ds, int port,
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index 8a8144868eaa..a71166e0a7fc 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -304,8 +304,6 @@  enum mt7530_vlan_port_acc_frm {
 					 MT7531_FORCE_DPX | \
 					 MT7531_FORCE_RX_FC | \
 					 MT7531_FORCE_TX_FC)
-#define  PMCR_FORCE_MODE_ID(id)		((((id) == ID_MT7531) || ((id) == ID_MT7988)) ?	\
-					 MT7531_FORCE_MODE : PMCR_FORCE_MODE)
 #define  PMCR_LINK_SETTINGS_MASK	(PMCR_TX_EN | PMCR_FORCE_SPEED_1000 | \
 					 PMCR_RX_EN | PMCR_FORCE_SPEED_100 | \
 					 PMCR_TX_FC_EN | PMCR_RX_FC_EN | \